Rail hardening method and apparatus



Jan. 10, 1939. R. E. FRIC KEY 2,143,347

RAIL HARDENING METHOD AND APPARATUS Filed July 27, 1936 X EH F-IE J 'IIQTIEI E F IE 4 I INVENTOR. Eaya/ 4. Fr/c'ley BY C ZWQMM ATTORNEY.

Patented 1.... 10,1939

UNITED STATES PATENT OFFICE to Welding Service, I

nc., San Francisco, Calif.,

a corporation of California Application July 27, 1936, Serial No. 92,716

9 Claims.

and apparatus for the treatment of railroad rails, to effect hardening of the ends of rail sections. In Frickey et al., Patent No. 2,013,461, there is disclosed a rail treatment method making use of a. heating operation, followed by a chilling or quenching operation. Heating is confined to the localized area at one end-of a rail or rail section, to heat an upper layer of metal in the rail ball above the so-called critical temperature, as for example a temperature of about 1500" F. Chilling is carried out by the use of a chilling liquid, such as oil, and by the use of liquid retaining means, whereby virtually a pool or blanketof l5 liquid is applied to the heated area. Chilling-is carried out under controlled conditions, whereby when the heating operation is properly controlled, a predetermined degree of hardness is secured which can be duplicated within relatively close limits for successive operations.

Hardening of rail ends serves primarily the purpose of minimizing deterioration of rail joints. through pounding of rolling stock upon the rail ends. I have found that rail ends are better able to withstand such deterioration, when the greatest amount of hardening is in a limited zone at the end of the rail, with the remainder of the heat treated area tapering off in hardness, to the hardness of the untreated rail metal, which so with ordinary rolled carbon steel rails, is in the neighborhood of 260 Brinell. Excessive hardness at any point in the treated area is apt to cause the metal to become too brittle, with the result that fractures may occur and the metal may break away. Insufficient hardness at the end of the rail will not properly minimize flow of metal under the pounding action of the roll-.

ing stock. with an optimum hardness pattern,

such as will subsequently be described, I have found that the metal at the end of the rail can attain a fair degree of hardness, as for example in the neighborhood of 400 Brinell, toafl'ordthe results desired. The method and apparatus described in said Patent No. 2,013,461 may not afford the optimum hardness pattern described herein, because the chilling rate of the liquid applied to the heated area of the rail is relatively uniform throughout the area, except for variations in the temperature to which the area is initially hea In view of the foregoing, it is an object of the present invention toafford a method and apparatus of the above character, which will make possible an optimum hardness pattern for the 5 ends of rail sections.

Morespecifically the pres- This invention relates generally to methods 4 ent method and apparatus controls the rate with which the chilling liquid absorbs heat from the heated area, whereby the greatest degree of hardness issecured in a limited zone at the end of the rail section. 5

Further objects of the invention will appear from the following description in which the preferred embodiment of the invention has been set forth in detail, in conjunction with the accompanying drawing. 10

Referring to the drawing:

Fig, 1 is aside elevational view, showing apparatus incorporating the present invention, and being partly diagrammatic.

Fig. 2 is a cross-sectional detail, taken along 15 the line 2-2 of FIG. 1.

Fig. 3 is an enlarged cross-sectional detail, taken along the line 3-3 of Fig. 1.

Fig. 4 is a diagrammatic view illustrating an optimum hardness pattern.

The representative type of apparatus illustrated in the drawing consists of an open bottomed receptacle or liquid retaining means l0, which is-adapted to be seated upon the upper surface of a rail II. For the purpose of adapting the as receptacle to different size rails, its lower portion can include an adapter ii. To effect a proper liquid seal with the upper surface of the rail ball. the lower edge of the adapter I! is shown provided with a slot or groove If, to receive a suitable so packing. it, such as a packing made of asbestos. Likewise a packing I6 is showninterposed between the adapter i2, and the remainder of the receptacle i0. Communicating with the receptacle l0 there is a pipe H, for introduction of a 35 chilling liquid, and also a pipe l8, for removal of liquid. Within the receptacle l0, pipe l8 can communicate through the lower end of a stand pipe l9, which is shown provided with a suitable check valve 20. 40

For the purpose of modifying the chilling effect of the liquid over a part of the heated area,

bailie means is provided consisting of a strip of sheet metal 2!. When the receptacle I0 is seated upon a rail the metal strip 2i occupies a position 45 in close proximity with the upper surface of the rail ball, as shown in Fig. 3. For convenience it can be suitably secured to the receptable l0, as for example by having the ends of the metal strip b'ent upwardly, and inserted within the grooves so It. Ordinarily no effort is made to space the metal strip II from the upper face of the ball, although in practice surface irregularities of the rail, and irregularities in the strip 'of metal, pe'rmit substantially the entire area covered by the I I three inches.

u but for that portion of the'heated area covered strip 2| to be contacted with liquid, even though certain points on the strip may be in contact with the rail.

The apparatus utilized in conjunction with container ill, for applying a chilling liquid such as 011, should be such that the chilling liquid can be applied under controlled conditions, to produce the desired predetermined results in successive operations. For example, in general conformance with the disclosure of said Patent No. 2,013,461, liquid can be introduced into pipe H, from a tank 23, by opening the valve 24. The liquid can be removed from pipe is, by pump 26, which is shown delivering the liquid through a cooler 21, back to the storage tank 23. Tank 23 can be provided with suitable thermostatically controlled heating means, whereby the liquid permitted to fiow from this tank through pipe i1, is maintained at a constant temperature. Operation of valve 24, and also the operation of pump 26, can be correlated through an automatic control, whereby pump 26 is started in operation after a predetermined interval following opening of valve 24, with automatic closing of the valve 24 after a predetermined interval of time, followed by automatic stopping of pump 26. With such features of control it. is evident that a liquid is first submitted to the receptacle ID, to blanket the area of the rail ball encompassed by the same, with the chilling liquid. Thereafter chilling liquid is circulated through the container l0, until valve 24 is closed, after which the remaining liquid-is pumped out through pipe I 8, to terminate the chilling operation.

Use of the apparatus described above, in the a carrying out of the present method, can be described as follows: An upper area of the rail ball at the end of the rail is heated by suitable means whereby an upper layer of metal in the rail ball attains a temperature substantially above the critical temperature of the rail metal. For example this heating operation can be carried out by rapidly traversingan electric are over a predetermined area of the rail ball, whereby the heat of the arc is distributed over said area, to eflect a penetration of heat (to a temperature above the critical temperature of the metal) to a suitable depth, as for example a depth of about V inch. In practice this area can extend substantially entirely across the width of the rail ball, and for a suitable distance back from the end of the rail, such as a distance of about This heating is carried out under such controlled conditions that the results can be duplicated in successive operations, within relatively close temperature tolerances. For ex ample when heating electrically, the electric in put can be maintained relatively constant, and the heating discontinued after a predetermined amount of electrical power consumption. After such a heating operation, the container I6 is applied to the end of the rail, over the heated area,

and a quenching operation, is carried out; as described above.

In the foregoing, reference has been-made to a representative heated area extending back for a distance of about three inches from the end of the 7 rail. Under such conditions it is satisfactory-to have the metal strip 2! about an inch andonequarter wide, and located about one inch from the end of the-rail, when the container is seated upon the rail as shown in Fig. 1. Chilling liquid introduced into the container I I blankets the heated area, to effect a rapid absorption of heat,

by metal strip 2i, heat absorption occurs at a materially slower rate, 'due to a bafiling eflect, which presumably minimizes convexion currents in the liquid pool, and also possibly permits some gas pockets to form between this strip and the heated surface of the rail. In any event it has been found that the use of such baiiling means serves to taper off the hardness from a limited zone of greatest hardness at the end of the rail, to the hardness of the untreated rail metal. Thus an optimum hardness pattern such as shown in Fig. 4, can be produced or approximated. In this figure, the initially heated area on the upper surface of the rail ball, has been indicated. Likewise the extent of the baille in a direction longitudinal of the rail, and the positioning of this ness pattern such as shown in Fig. 4, is in partattained or approximated by virtue of a drawing action following the chilling operation. In other words in usual practice the chilling operation is discontinued while there .is still suflicient heat in the rail to effect the drawing operation, and thereafter fiow of heat back into the chilled area causes the hardness of the metal to be modified. In carrying out such a drawing operation it isevident that modification of the chilling action of the liquid, by use of the baflle means 2|, will occasion a greater amount of tempering or drawing, for the areas influenced by its proximity. Generally the bailie means 2| need not be of greater extent because the area remote from the end of the rail which is not covered by the baflle is at.a somewhat lower temperature than the metal near the end of the rail, at the time the chilling operation is commenced, due to flow of heat into the body of the rail. Likewise such portions ofthe heated area tend to be modified to agreater degree by the drawing operation.

I claim:

1. In a method of hardening rail ends, heating an upper layer of metal in the rail ball for an area extending a susbtantial distance along the length of the rail from the end thereof, and then diiferentially chilling said area to afford a resulting surface hardness pattern, such that the greatest deg ee of surface hardness is secured in a limited zone of said area at the end of the rail, while for the remainder of said area the surface a hardness decreases to a value comparable to the diflerentially chillingthe upper surface of said area to aiford a resulting surface hardness pattern such that the greatestdegree of, surface hardness is secured in. a limited zone of said area at the end. of the rail, while for the remainder of said area the surface hardness decreases to a value comparable, to the hardness of the unheated rail metal, said differential chilling-being efiected by the use of a fluid which. is.contacted with the heated area..

. v3.-;In a method of hardening rail ends, heating an upper layer of vmetal in the rail ball for an area extending a substantial distance along the length of the rail from the end thereof, contaet ing a chilling liquid with substantially the entire upper surface of the heated area and controlling the chilling effect of the liquid for a certain portion of the heated area, whereby a predetermined hardness pattern is secured for the upper surface of the rail.

4. In a method of hardening rail ends, heating an ,upper layer of metal in the rail ball for an area extending a substantial distance along the length of the rail from the end thereof, contacting a chilling liquid with substantially the entire upper surface of the heated area, such chilling liquid being applied in a manner as to blanket said area, and-then controlling the chilling efiect of the liquid in such a manner that in a given period of time more heat is absorbed from a limited zone of said area at the end of the rail, than for the remainder of said area.

5. In rail chilling apparatus of the character described, an open bottom liquid retainer adapted to be seated upon a rail ball at one end of the rail section, means for sealing the lower edges of the retainer with respect to the ball of the rail, whereby liquid introduced into the retainer is caused to blanket a limited area of the rail ball, and means within the retainer for modifying the chilling action of said liquid for certain portions of said area. i

6. In rail chilling apparatus of the character described, an open bottom liquid retainer adapted to be seated upon a rail ball at one end of a rail section, means for sealing the lower edges of the retainer with respect to the ball of the rail whereby liquid introduced into the retainer is caused to blanket a limited area of the rail ball, and baifle means within the retainer for modifying the chilling action of liquid for certain portions of said area.

7. In rail chilling apparatus of the character described, an open bottom liquid retainer adapted to be seated upon a rail ball at one end of a rail section, means for sealing the lower edges of the retainer with respect to the ball of the rail, whereby liquid introduced into the retainer is contacted with a limited area of the rail ball, and baiile means overlying a portion of the surface of said area, said ballle means being spaced from the end of the rail and serving to reduce the rate of chilling effected by the liquid introduced into the retainer for said portion.

8. In rail chilling apparatus of the character described, for application to a rail, after an area of the rail, near the end of the same, has been heated, means for blanketing a limited upper area of the rail ball with a chilling liquid, and baffle means comprising a strip of metal, overlying a portion of said area and in relative close proximity to the same.

9. In rail chilling apparatus of the character described, an open bottom liquid retainer adapted to be seated upon a rail ball at one end of the rail section, means for sealing the lower edges of the retainer with respect to the ball of the rail, whereby liquid introduced into the retaineris contacted with a limited area of the rail ball encompassed by the retainer, and battle means consisting of a strip of metal extending across the lower face of the retainer and adapted to span the upper surface of the rail ball, said strip of metal being spaced from that end of the retainer adapted to be disposed at the end of the rail.

ROYAL E. FRICKEY. 

